Vehicles are increasingly employing sophisticated internal communication systems and networks allowing the exchange of data between the various modules and components within the vehicle. Since such communication systems typically include a data bus interconnecting all the modules, such that any module on the bus may send messages to any other module on the bus, it is desirable to provide authentication of messages sent from one module to another over the data bus in order to prevent replay-attacks, denial-of-service attacks, and other such security issues.
While it would be desirable to transmit security-related data within the payload of each message transmitted over the bus (e.g., in the form of an anti-replay attack counter), the size of the payload used for typical messages cannot accommodate such data. For example, in a system that utilizes a message payload of 64 bits, it would be impractical to use a significant portion of that payload for a counter that might itself be 32-64 bits. Furthermore, it is common for messages to be sent over the bus at a high periodic rate (e.g., once every 10 ms). Transmitting additional data (such as a 64-bit anti-replay attach counter) at that rate would undesirably increase bus utilization.
Accordingly, there is a need for improved systems and methods for providing secure communication in the context of vehicle communication systems.